bis(2-ethylhexyl) (4-hydroxy-3,5-dimethoxybenzyl)malonate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-04-26 to 2006-07-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

adopted 24 April 2002

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Version / remarks:

29 December 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

471-510-2

EC Name:

-

Cas Number:

872182-46-2

Molecular formula:

C28H46O7

IUPAC Name:

1,3-bis(2-ethylhexyl) 2-[(4-hydroxy-3,5-dimethoxyphenyl)methyl]propanedioate

Test material form:

liquid: viscous

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Strain: Albino rabbit, Crl:KBL(NZW)BR, female (f)
- Source: Charles River Wiga GmbH, Kißlegg
- Age at study initiation: about 19 to 20 weeks
- Weight at study initiation: 4,14 kg (mean)
- Housing: Becker, type K99/30 KU, floor area approx. 5400 cm2
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature: 19 - 22°C
- Humidity: 42 - 71%
- Photoperiod: 12 hours light, 12 hours dark

IN-LIFE DATES: From: 2006-05-03 To: 2006-05-25

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0,5 ml

Duration of treatment / exposure:

4 hours

Observation period:

1, 24, 48, 72 hours after removal of patches up to 15 days after start of treatment

Number of animals:

3 female rabbits

Details on study design:

Identification and adaptation
Healthy rabbits were allocated to the study group. The animals were kept in the experimental room for more than 7 days to allow them to acclimatize. Each animal was uniquely identified by a tattoo in the ear displaying the animal number. Individual cage cards were affixed to each cage displaying the study number, test material, day of treatment, and animal number.

Assignment
3 female rabbits were used for this study. The mean initial body weight at the start of the study was 4.14 kg.

Housing and diet
All rabbits were housed in an air-conditioned room of about 50 m2. A timer to provide a 12-hour light and a 12-hour dark regime controlled lighting.

Animals were kept separately in special rabbit cages (manufacturer: Becker; type K99/30 KU, floor area about 5400 cm2, a shelter with an integrated sitting board of about 1820 cm2; overall height: 60 cm) with plastic grids placed on mobile racks. The collection pans underneath the cages were cleaned at least three times per week. The cages were cleaned before the start of the study.

Temperature and relative humidity were measured using a thermohygrograph. The room temperature varied from 19 to 22 °C and the relative humidity varied from 42 to 71 %.

The rabbits received a commercial diet for rabbits, Provimi Kliba 3418.0 ad libitum and ssniff K snack, as well as fresh community tap water from Makrolon drinking bottles ad libitum.

According to the specifications given by the manufacturer, the diet had been checked by independent laboratories. Analysis included both qualitative and quantitative evaluation for heavy metals, aflatoxins, pesticides, and antibiotics.
The drinking water was periodically analyzed according to the German regulations for human drinking water.



Grading scale for evaluation (according to OECD Guideline):

Erythema and eschar formation
Scores
--------------------------------------------------
No erythema 0
Very slight erythema (barely perceptible) 1
Well defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness) to eschar
formation preventing grading of erythema 4
--------------------------------------------------
Maximum possible: 4
--------------------------------------------------

Edema formation
Scores
--------------------------------------------------
No edema 0
Very slight edema (barely perceptible) 1
Slight edema (edges of area well
defined by definite raising) 2
Moderate edema (raised approx. 1 mm) 3
Severe edema (raised more than 1 mm
and extending beyond area of exposure) 4
--------------------------------------------------
Maximum possible: 4
--------------------------------------------------

Total possible irritation score (maximum): 8

Mean score = Mean grading for erythema or edema of all the rabbits per time point
Mean cumulative score = Mean grading of all readings for erythema and edema per time point
Mean score per animal = Mean grading for each animal of erythema or edema (24, 48, and 72 hours after removal of the patches)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 8 days

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 8 days

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 8 days

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.67

Max. score:

4

Reversibility:

fully reversible within: 6 days

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Other effects:

No signs of clinical toxicity were detected.
All animals survived the observation period.
Body weight development of the treated rabbits was inconspicuous.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item, undiluted, induced a weak erythema of the skin up to day 7. According to the EEC-Directive 2001/59 the test material should not be classified as a skin irritant.

Executive summary:

Purpose

The purpose of this assay was to identify the skin irritation/corrosion potential of the test substance when applied to the intact skin of previously shaven rabbits for a 4 hours period under semiocclusive conditions. This study should provide a rational basis for risk assessment to the irritating potential of the test item in man.

Study Design
To test for primary skin irritation, 0.5 mL of the test material, was spread onto 6 cm²patches and applied to the intact skin of previously shaven rabbits for a 4 hours period under semiocclusive conditions. The study was started as an initial test with one animal and followed by the confirmatory test with two further animals. The first examination of the treated skin sites followed 1 hour after removal of the patches. Thereafter, examinations were performed daily for further 14 days.

Results

Under the conditions of the present study, erythema (score 1) from day 1 up to day 7, and in one animal edema (score 1) from day 3 up to day 5 of the experimental part, were seen. Furthermore all three animals showed scales from day 6 up to day 11 of the experimental part.

Evaluation of all animals (mean score):

Day (after treatment)	1 (1h)	2 (24 h)	3 (48h)	4 (72 h)
Erythema	1	1	1	1
Edema	0	0	0.33	0.33

Evaluation of each animal:

Animal No	Mean score (24, 48, 72 h)			Maximum value (24, 48, 72 h)
	16	17	18	16	17	18
Erythema	1	1	1	1	1	1
Edema	0.67	0	0	1	0	0

Conclusion

The test item, undiluted, induced a weak irritation of the skin up to day 7.